//定时器？
console.log('start') //1

setTimeout(() => {
  console.log('timeout') //7
}, 0)

async function async1() {
  console.log('async1 start') //2
  await async2()
  console.log('async1 end') //5
}

async function async2() {
  console.log('async2') //3
}

async1()

Promise.resolve().then(() => {
  console.log('promise') //6
})

console.log('end') //4